Gas gauge trippin out.... Help!

[NuthinFancy]

Simlpy my gas gauge turns on the low fuel light at half of tank . Now I connected the cluster to my buddies e30 and the gas gauge read fine and on point to what his said before ...today I'm driving around and like I said at half of tank the low fuel light came on I don't want it to go any further cuz I don't want to run out of gas but can it be anything else besides the cluster???...

[Killacortes]

could be the fuel level sender. there are two of them right under your back seat. there are two access points one has the sender and the pump on behind passenger side and the other is behind drivers side

[jlevie]

It would be helpful to know what car this is and whether the cluster is orginal.

The low fuel warning light is operated by a switch in the right side level sensor. If it is on that side on the tank only has about two gallons in it, regardless of what the gage shows. On an early model car with only a single level sensor, the gage problem could be a bad sensor or the wrong gas gage if the cluster has been replaced. On a late model car with two sensors one could be bad or the siphon could be in-op.

[NuthinFancy]

The car is a 1988 325e but it has the 325I motor , 4door if it makes a difference and honestly I don't know if the cluster was ever changed ...but it has to be some kind of sensor cuz when I plugged it up to my friends e30 it went lower than half tank with out the light coming on. Still don't know wat sensor it could be ..

[Dolmangar]

My guage drops like a stone once it hits half tank. It's a replacement cluster (from PO) so I don't know where it came from. I assumed that it was a difference in years / gas tanks / etc that caused it to do it. Anyone have a way to map year to a particular guage so the correct one can be found used?

[NuthinFancy]

^^^ Yea that info would be kool

[Jean]

Test the fuel level sensor(s) before doing anything with the cluster/gauge.

[jlevie]

An 88 should have the 63L tank and two level sensors. In which case I'd suspect that the one on the left side is bad.

[NuthinFancy]

May I ask why u said the left and not the right? If u would of said the right I would of asked this question of why not the left ..jus trying to find out more info for myself I guess ...if you can explain a little that be awsome for me too...thnx

[Jean]

Because one has the on/off switch in it that turns the light on/off.

[NuthinFancy]

Kool ill check on that ...thnx

[jlevie]

May I ask why u said the left and not the right? If u would of said the right I would of asked this question of why not the left ..jus trying to find out more info for myself I guess ...if you can explain a little that be awsome for me too...thnx

The float in the right side sensor is falling to the bottom, or else the low fuel light would not be coming on. Thus my first suspect would be the left side sensor being stuck.

[NuthinFancy]

^^^ make sense thnx bro...

[hurttech]

When the gauge is at half full is your tank actually half full, or empty? I have the exact same problem with a swapped cluster. When the needle hits 1/2 the light comes on, however my tank is indeed nearing empty.